Manufacturing of biocompatible and biodegradable stents in AZ31 magnesium alloy

Magnesium alloys are novels to the stent industry as they provide the balance between required mechanical properties for a stent and biodegradability in the human body. Stent production traditionally conducted by the reproduction of the stent mesh with the pulsed laser systems aided with CAM systems with good reproductivity and high presicion. This work aims to define a stable production chain made by two main steps: laser micromachining and chemical etching to manufacture biodegradable and biocompatible stents in AZ31 Magnesium alloy and make qualitative assessments on the results. Before laser processing, the system is adapted to tubular cutting with corresponding designs and manufactures to aid the laser microprocessing system. Due to the shortage of the tubular magnesium in required dimensions (d = 2÷2.5 mm, t =0.2÷0.25 mm), the laser process parameters are firstly studied on AISI 316L grade stainless steel tubes and best acquired results are implemented on magnesium alloy laser processing operations. Laser microprocessing studies on AZ31 are conducted on sheets, and the qualitatively best acquired results are tried on tubular cutting. Both stainless steel and AZ31 tubular stensts are cut, where they are chemically etched for afterwards for spatter and removal and finalize scrap seperation. Acquired results with different assisting gases are analysed.